As we were starting up the hill on Market in Kirkland I went to shift down into granny and thought that the chain had broken. Instead it was the crank!
On this same bike (the Ibis tandem) I had a chain ring bend a little when I wedged the chain between two rings, and on another bike (the Fuji Touring) I torqued the spider so that the rings wouldn’t lay flat. I think that I’m done with Rene Herse cranks, at least on tandems. I really like how they look but I’ve never had cranks that broke on me.